Over-current during steady state operation:

1. Short-circuit at motor output.
2. Sudden increase in motor loading.
3. AC drive output capacity is too small.

1. Check for possible poor insulation at the output line.
2. Check for possible motor stall.
3. Replace the AC drive with one that has a higher output capacity (next HP size).

Check drive rectifier & IGBT using multimeter.
Check wiring.
Check drive hardware using multimeter.